Water purification and dispensing system

ABSTRACT

A water purification and dispensing apparatus comprises a water inlet for obtaining water from a supply source and a water purification system with filters for removing impurities from the source water to produce purified water. The water purification system is designed to respond to a demand condition for purified water by recirculating purified water in the apparatus to flush the filters of the water purification system. The apparatus also includes a mineralization system and has a dispensing system for dispensing the mineralized purified water into containers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application, Ser. No.07/947,125, filed Sep. 17, 1992, now U.S. Pat. No. 5,427,682, whichapplication is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to water purification and dispensingsystems and processes for purifying and dispensing water.

Consumers are becoming more aware of the deterioration of the quality ofthe water supplies from their city, rural water system or private wellsystem. Many retailers currently sell bottled water and other beverageproducts in off-the-shelf containers. Some retailers use point ofpurchase dispensers that purify water and dispense it into a containerprovided by the consumer. Other people have bottled water delivered totheir homes or business, often in 5 gallon containers designed to fit ona water cooler. The market for these forms of bottled water is emergingto the point where purified water is a basic commodity.

One problem with any of these sources of bottled water is productquality. Presently there is a concern that bottled water may not be allthat much better than tap water. On top of this, the variousdistribution systems have drawbacks.

Where bottled water is sold off the shelf, there are costs involved intransporting the water from the bottled water plant, through thewholesale and retail distribution system, storing the water atwarehouses and in the back room at retailers, and stocking shelves, notto mention the shelf space taken up by the product. Also, the timebetween when the water is produced and bottled and when the consumerpurchases it may be a period of weeks and even months. Of course,leaking bottles-also cause a problem, such as when a pallet of cases ofbottled water are stacked in a warehouse or the back room of a store.

Delivered bottle water is generally more expensive because of thedelivery costs, and is also subject to some of the disadvantagesdescribed above. In addition, the delivery process itself hasdisadvantages, such as the scheduling of delivery times and thepossibility that delivery personnel or equipment will track in mud ordirt into the office or other place of use.

One problem of water quality is of course when the purification is notcomplete. However, if all impurities are removed from the water, it mayhave a reduced pH that then causes the water to leach minerals or otherharmful components from processing equipment, storage containers, andeven the body when the water is consumed. It is a common experience toopen a container of bottled water and find that is has acquired an offtaste, especially when stored in some plastic containers.

Point of sale dispensing of water overcomes some of the drawbacks ofother bottled water distribution systems, but also presents newproblems. First, because the dispensing equipment is used by the public,it is subject to contamination. Also, even if the water is purified,there is no control over the cleanliness of the container into which itis dispensed. Often, to reduce costs, many water purification anddispensing systems have a small processing capacity coupled with astorage tank. Thus, water is purified on a slow, continuous basis, butis stored to meet demand. These large storage systems present longholding times that are not conducive to water purity, and if the tanksare not sealed, to the possibility of contamination.

With these various drawbacks, there is room for considerable improvementin water purification and dispensing systems and processes.

SUMMARY OF THE INVENTION

In one aspect, the present invention is a water purification anddispensing apparatus comprising a water inlet for obtaining water from asupply source, a water purification system for removing impurities fromthe source water, a mineral addition system for adding desired mineralsinto the purified water and a dispensing system for dispensing themineralized, purified water into containers; wherein the purification,mineral addition and dispensing systems are contained in a singleapparatus that can be transported to a location and connected to a watersupply source.

In another aspect, the invention is a water purification and dispensingsystem comprising an inlet for connection to a water supply source, awater purification system for removing impurities from the source water,a dispensing station for dispensing the purified water into containersand a container washing station for washing containers prior to thecontainers being filled with purified water.

In another aspect, the invention provides a process for purifying,mineralizing and dispensing water comprising the steps of obtainingwater from a supply source, purifying the source water by passing itthrough a reverse osmosis membrane, adding minerals into the purifiedwater and dispensing the purified, mineralized water into a container.

In another aspect, the invention provides a process for purifying anddispensing water comprising the steps of obtaining water from a supplysource, purifying the source water by contacting the water with areverse osmosis membrane to create purified water and concentrate,dividing the concentrate into a waste stream that is discharged and arecirculation stream that mixes with water from the supply source priorto contacting the water with the reverse osmosis membrane, routing thepurified water to a water dispensing system until there is no moredemand for purified water, and reducing the level of impurities in themixed water brought into contact with the reverse osmosis membranebefore stopping purification and stopping the flow of water contactingthe reverse osmosis membrane.

This system allows grocers to reduce the hours necessary to constantlyrestock empty shelves, it saves on stockroom storage space for bulk orboxed water and reduces investment in inventory of empty watercontainers.

In addition to overhead cost savings, the invention makes it possible tooffer water from this system at a competitive price.

In addition, the grocer can use purified water from the apparatus of thepresent invention as tributary water for ice machines, floraldepartments, produce misters, delicatessens and other areas.

The purified water does not contain contaminants such as chlorine,pesticides, lead or other chemicals often found in many municipal watersystems. In addition, it is more healthy than many of the purifiedwaters on the market due to the addition of minerals in the preferredprocess. The water of the preferred process of the present invention isbetter tasting than most other sources of drinking water. The reusablecontainers recommended for the system do not leave or alter the tasteand odor of the water like many of the containers currently used now,and they can be reused many times, thus reducing the waste going intolandfills or over burdened recycling operations and saving the disposalcosts.

These and other benefits of the invention, as well as the inventionitself, will best be understood in view of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the preferred water purification anddispensing apparatus of the present invention.

FIG. 2 is a schematic drawing of the water flow components of theapparatus of FIG. 1.

FIGS. 3A-3F are schematic representations of the control program used bya microprocessor to control the apparatus of FIG. 1.

FIG. 4A is an exploded view of a preferred reverse osmosis unit used inthe apparatus of FIG. 1.

FIG. 4B is a cross-sectional view of the reverse osmosis unit shown inFIG. 4A.

FIG. 5 is a schematic representation of the ultraviolet light treatmentmodule used in the apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS OF THEINVENTION

The various aspects of the invention may all be embodied in one waterpurification and dispensing apparatus or system, the preferredembodiment of which is shown in FIG. 1. The preferred apparatus 10comprises a cabinet 12 housing various component parts (not shown) andhaving an access door 14, a container washing station or compartment 20,a container filling station or compartment 30, a control panel 40 and adisplay panel 60.

The preferred container washing compartment 20 is positioned behind atransparent door 22. Inside the compartment 20 is a place forpositioning a container 16 upside down over a spraying nozzle (notshown). Alternately, a bottle cap wash compartment (not shown),including a nozzle for washing a bottle cap placed therein, may beincluded in compartment 20. The bottom of compartment 20 is connected toa drain line which leads into a sump inside cabinet 12. In this way,washing and rinse water drains out of the compartment 20. Alternately,the purification system and dispensing station are contained in oneapparatus and the washing station is contained in another apparatuslocated nearby. Also, the container washing station may use water fromthe water purification system to wash the containers.

The container filling station or compartment 30 is also closed by atransparent door 32. As shown in FIG. 5, lasers 34 are used to positionthe container 18 under a fill spout 36 that is positioned above the top38 of the compartment 30. Alternately, more than one filling compartmentmay be used. The top 38 has three small holes through it for passage ofthe light from lasers 34 and purified water from the fill spout 36. Thefloor 39 of compartment 30 is connected to a drain line 37 which alsoempties into the sump inside cabinet 12. The container 18 rests on astainless steel grid 33 positioned atop the floor 39.

The preferred control panel 40 includes six push buttons 41-46 and eightlights 51-58. Button 41 is a "stop" button, preferably colored red,which can be pushed by a customer anytime it is desired to shut off theoperation of apparatus 10. Buttons 42, 43 and 44 are labeled as "1Gal.", "2 Gal." and "3 Gal." respectively. One of buttons 42, 43 and 44is pushed to dispense the desired amount of purified water, depending onthe size of container 18. Preferably, the container 18 is apolycarbonate container designed for use in water coolers. Button 45 isa "top off" button, used to dispense purified water for as long asbutton 45 is activated. Button 46 is a "wash/rinse" button foractivating the wash cycle of the apparatus 10, described below.

Display panel 60 includes a counter 62 and top and bottom LED displays64 and 66. These are used to monitor the operation of the apparatus 10.Counter 62 shows how much purified water has been dispensed and displays64 and 66 are used for diagnostic purposes.

The various internal water flow components of apparatus 10 are depictedschematically in FIG. 2. Water from a supply source, such as city water,enters the system at inlet 102. Preferably, the source water has beentreated with a water softener. The water next flows through a back flowpreventer 104, then through an activated granulated charcoal filter 106.Next in line is a prefilter 108, preferably sized to remove anyparticles over three microns. The charcoal filter 106 and prefilter 108are designed to reduce the amount of purification that has to take placeat the reverse osmosis membranes.

Next, the pretreated water flows through a solenoid inlet valve 110.This valve is opened to begin operation of the system. An inlet pressureregulator 112 is used to control the inlet pressure, preferable at 40psi, so that downstream operations of the system can be consistent (andthus uniform parts can be used in different machines) even though thesource water supply pressure may be different at different locationswhere the apparatus 10 is installed. A pressure gauge 114 and inletsafety pressure switch 116 are positioned after the inlet pressureregulator 112. The inlet pressure safety switch 116 is in the controlsystem for the apparatus 10.

The prefiltered source water is next pressurized by pump 118, preferableto 250 psi, to provide the necessary pressure for the reverse osmosistreatment. Preferably three reverse osmosis units 120, 121 and 122contained in specialized full flow housings (shown in FIGS. 4A and 4Band described below) are connected in series as shown in FIG. 2.Purified water flows out of a reverse osmosis unit 120, 121 or 122 intoline 123. Alternately, a nano-filter or ultra-filter may be used. Theconcentrate, containing a higher level of impurities, from unit 120serves as the feed for unit 121. The concentrate of unit 121 is fed intounit 122. The concentrate of unit 122 flows to line 124, past aconcentrate pressure gauge 126 and through a concentrate pressure adjustvalve 128. The concentrate stream is thereafter divided into a wastestream and a recirculation stream. The waste stream flows through avalve 130, a flow meter 132 and to drain 134. The recirculation streampasses through line 136 and mixes with the water from the supply source.This recirculation of a portion of the concentrate allows the reverseosmosis membranes to be more efficient because it increases the flowrate and hence the velocity of the water in the reverse osmosis units120, 121 and 122, which prevents the membranes from getting plugged aseasily. Alternatively, the concentrate could all be sent to the wastestream and more source water used in a single pass. However, this wouldsubstantially decrease the amount of purified water produced compared tothe source water used. In many localities, water conservationrequirements would prohibit such a waste of water. In a preferredembodiment, valves 110, 128 and 130 are adjusted so that the flow ofinlet source water is 3 gallons' per minute, the recirculation stream inline 136 is 1.1 gallons per minute, the waste stream going to drain 134is 0.8 gallons per minute, producing 2.2 gallons per minute of purifiedwater in line 123.

The purified water in line 123 is measured for resistivity by aconductivity sensor 138. The sensor is set to shut down the system ifthe output from the reverse osmosis units 120, 121 and 123 has aresistivity less than 20,000 ohms/cm., which correlates to greater than15 ppm total dissolved solids. The purified water next flows throughcheck valve 140 and past a junction at which the purified water goeseither into the dispensing system, if there is a demand for purifiedwater, or through line 142 and check valve 144 to be mixed with sourcewater and recirculation water. Line 142 is used as a quality flushsystem in two instances, when the purification system starts up and whenit shuts down.

At the beginning of a cycle, purified water that has been sitting in thesystem is recycled through the system, just to assure that dispensedwater has the highest possible quality. (However, this purified watermay be used in the wash cycle.)

At the end of the demand for purified water, the level of impurities inthe mixed source water and recirculation water (which is then feed waterto the reverse osmosis unit 120) is reduced before the purificationsystem is stopped. This "flushing" operation improves the life of thereverse osmosis membrane because the impurity level in the water left incontact with the membrane is minimized when the flow of water contactingthe membrane has been stopped. Alternately, a separate valve forflushing concentrate from the system may be used. This is achieved bycontinuing to discharge waste water at the same rate, but substantiallycutting down on the flow of source water and making it up with a flow ofpurified water. For example, the inlet flow rate may be reduced from 3gallons per minute to 0.8 gallons per minute when the 2.2 gallon perminute purified water starts flowing through line 142 rather than intothe dispensing system. After a time, the level of impurities in the feedwater to the reverse osmosis unit 120 will approach that of the sourcewater.

During normal operation, when purified water is being supplied to thedispensing system, the concentrate will have a level of impuritiespreferably of at least 2,000 ppm. and more preferably at least 3,000ppm. However, by the time the flow of water contacting the reverseosmosis units 120, 121 and 122 is stopped, the level of impurities inthe concentrate is preferably no more than 1,500 ppm, and morepreferably less than 1,000 ppm.

In the preferred embodiment, the dispensing portion of the systemcomprises a wash and rinse section, a storage section, an auxiliary feedsection, a mineralization section and an ultraviolet radiation/fillsection. When the wash cycle button 46 is activated, purified waterentering the dispensing portion of the system through line 146 will gofirst through solenoid wash valve 148 or later through solenoid rinsevalve 150, before going to spray nozzle 152 located in the bottom ofwash compartment 20. Purified water going through wash valve 148 alsogoes through proportional feed pump 154, which injects a washing andsanitizing solution from a storage reservoir 156 into the wash water.The washing and sanitizing cycle is used to wash the bottle.Additionally, this cycle may be used to wash the bottle cap.

The washing and sanitizing solution may be a chlorine solution, thoughany chlorine odors emanating from the apparatus 10 may give customers awrong impression about the purity of water being dispensed. A preferredwashing and sanitizing solution is Roccal II sanitizing and deodorizingagent from National Laboratories, mixed at a ratio of one ounce of agentin one gallon of wash water. Of course, the proportional feed pump 154may be adjusted to inject any desired ratio of washing and sanitizingagent into the wash water.

If there is a demand for purified water, either to fill the storage tank158, for filling a container, or for auxiliary use, back flow checkvalve 160 and solenoid control valve 162 will open. The storage tank 158is preferably a bladder tank, also known as a hydropneumatic tank. Whenthe internal pressure of the air on one side of the bladder is below thepressure in the line connected to the tank, such as when there is noother demand for purified water, purified water will flow into the tank.When that pressure drops, such as when a container is being filled,purified water will flow out of the tank.

A supply demand pressure switch 164 after the bladder tank 158 senseswhen the pressure in the tank is so low that additional water needs tobe purified.

Purified water may be supplied to auxiliary uses through check valve 166and auxiliary supply valve 168. Where the apparatus 10 is located in agrocery store, purified water may be supplied for such other storefunctions as misting of vegetables, ice making equipment, coffeemachines, soft drink dispensing machines and the like. Preferably ameter 170 will be attached to the auxiliary line to measure such otheruses of purified water so that the level of use can be monitored forreasons such as payment for equipment usage.

Before purified water enters the mineralization portion of the system,it preferably passes through a flow restrictor 172. The flow restrictorcan be set to a fixed limit, such as 3 gallons per minute, so thatmicroprocessor controls in the fill section can be time-based and yielda consistent volume of dispensed water.

Next, the purified water passes through a proportional feed pump 174 sothat a set ratio of minerals may be injected into the purified water.The minerals added are preferably calcium chloride, potassium chlorideand magnesium chloride, preferably at a weight ratio of 60:20:20.Preferably, the minerals are injected at a level so as to bring thelevel of total dissolved solids in the mineralized water up to 100 ppm.These minerals not only make the water taste better, but they also makeit more healthful for drinking. They also bring the pH of the purifiedwater up to a point where it will not leach minerals or resins from thesystem or containers. Other minerals may be added or substituteddepending on the desired qualities of the dispensed water. Also flavorsor carbon dioxide could be added.

Preferably, the mineralized water flows next through a block cartridgecarbon filter 178. The filter 178 provides a good mixing action tototally dispense the minerals, as well as polishing the water byremoving any dissolved carbon dioxide in the water.

The last portion of the water system is a fill system with anultraviolet lamp to destroy any bacteria, shown in FIG. 5. Water entersa housing 180 containing an ultraviolet lamp 182. The housing 180 may beconstructed of polypropylene with a mirrored finish interior to reflectUV light back to the tubing 184 carrying the water. Preferably, thetubing is a thin wall, PFA Teflon tubing shaped into a helix. Fifteenfeet or more of tubing 184 may be formed into a suitable sized helix,which provides for a fairly long residence time for exposing the waterto UV light.

Next, the water passes out of the housing and through a set of solenoidfill valves connected in parallel, a fast fill valve 186 and a slow fillvalve, or top off valve 180, paired with a needle valve top off throttle190. Alternately, a fixed orifice may be used instead of the needlevalve 190. The top off valve 188 is used to prevent the water fromdraining from the fill tube 36 at the end of the cycle. Finally, thewater flows back into housing 180 and passes through another section oftubing 192, where it is further exposed to UV light, and out of filltube 36, discussed previously. This second pass of the water past the UVlight, and the UV light shining on the fill tube 36, assures that noairborne bacteria are able to contaminate either water in the fill tube36 or the fill valves 186 and 188. The fill tube 36 is raised above thetop 38 to prevent people from touching and thereby contaminating, thefill tube 36. Alternately, a shield guard (not shown) may be used toprevent access to the fill tube 36.

A photo resist sensor 194 is mounted by a port in housing 180 to detectif the UV light 182 should shut off or otherwise not provide thenecessary intensity. The output of this sensor and the other sensors inapparatus 10, as well as the push buttons 41-46, are preferably fed asinputs into a microprocessor, which then controls the various solenoidvalves. This control operation of the apparatus 10 can best beunderstood in view of FIGS. 3A-3F, which provide a schematicrepresentation of the computer program used to control themicroprocessor.

The control system of the apparatus 10 is schematically portrayed inFIGS. 3A-3F. FIG. 3A shows the control conditions necessary for pumpoperation. FIG. 3B shows the control conditions for operation of thewash and rinse system. FIG. 3C shows the control of the fill operation.FIG. 3D shows the control of the top off valve. FIG. 3E shows thecontrol of the alarm signals and FIG. 3F shows the control of thecounter 62.

There are numerous inputs into the microprocessor from the components ofthe system. These inputs have been labeled with the system componentreference numbers. For example, line 1 of FIG. 3A has an input from thesupply demand pressure switch 164. Some of the switches are normallyclosed, as is switch 164, and others are normally open, as are pushbuttons 42, 43 and 44 (lines 7-9). These normal conditions are depictedin the schematic.

Others of the inputs are based on the position of the various valves andthe pump 118. Again, these inputs are labeled with the reference numberused to depict those parts in FIGS. 1, 2 and 5.

There are three inputs from the apparatus 10 for which the componentparts are not shown in FIGS. 1 and 2. There is a wash/rinse compartmentdoor switch 24 (line 17), a fill compartment door switch 34 (line 26)and a sump overflow prevention switch 74 (line 48). (The sump hasanother float and a separate pump that will empty the sump whenever itreaches capacity. The sump overflow prevention switch 74 is set totrigger an alarm when the sump level goes above the normal point atwhich the sump is intended to empty).

The microprocessor has numerous timers, numbered 300, 301, 302 etc. thatare used for various control and delay sequences. These timers provideinputs to other microprocessor features, and the timers are thusrepresented in FIGS. 3A-3F in boxes when they are being set, and withthe same reference numbers without a box when they are used as an inputelsewhere. The preferred set time (in seconds) for the timers areindicated to the left of the boxes where the timers are shown being set.Whenever a break occurs in the circuit to the timer, the timer will bereset.

Several of the components, such as the valves and the pump 118, areactivated by the microprocessor. The reference number for that componentis then shown in a box, which represents a hard wired output. Forexample, line 3 shows the control conditions necessary to open valve110. On the other hand, the ultraviolet light 182 is on whenever theapparatus is plugged in.

The microprocessor also includes internal relays, numbered 400, 401 etc.These relays are used elsewhere for controlling other functions. Again,where the relay reference number is in a box, that line shows thecondition for activating the relay, and where the reference number isnot included in a box, it is used as a control condition.

The reverse osmosis membranes are preferably housed in a "full flow"housing as shown in FIGS. 4A-4B. The housing has a body 360 and a cap361, held together by a Victaylic clamp 362. Hence the body and cap eachhave Victaylic grooves 363 near their ends. The body 360 is otherwisecylindrical, with a plate 364 welded to the bottom to close the bottomend. Near the top of body 360 are two female nipples 365 and 366, usedto provide respectively an inlet and outlet to the body 360. The cap 361is used to seal the top of body 360, though the cap 361 has an outlethole 368 through the center of its top. A gasket (not shown) seals thecap 361 to the body 360.

Inside the housing is a standard reverse osmosis membrane unit 370. Theunit 370 has a pipe 371 going through its center into which the purifiedwater enters. In use, the pipe 371 is plugged at the bottom end with acap 390. An O-ring within the cap seals the pipe 371 and cap 390connection. The top end of pipe 371 extends through a coupling 392positioned in the cap 361 and through hole 368 in cap 361, and isattached to line 123 of FIG. 2. The coupling 392 includes an O-ring 393for sealing purposes. The unit 370 also includes a U-cup brine seal 372,which is sized to seal off the inside of body 360 between inlet nipple365 and outlet nipple 366. The reverse osmosis membrane 373 is actuallyencased in a fiberglass outer wrapper 374. Water entering the reverseosmosis unit 120 thus flows in through an inlet nipple 365, down throughthe reverse osmosis membrane 373 and is deflected by end plate 364 sothat it travels back up along the inside wall of body 360, but outsideof the fiberglass outer wrap 374, where it then exits through outletnipple 366 and is routed to the next reverse osmosis unit 121. Each ofunits 120, 121 and 122 are preferably constructed using the full flowhousing of FIGS. 4A-4B.

The preferred microprocessor is a Micro-1 programmable controller fromIdec Corporation, 1213 Elko Drive, Sunnyvale, Calif. The counter 62 ispreferably an Omron counter model H7EC-B from Omron Electronics, Inc.,One East Commercial Drive, Schaumburg, Ill. The preferred reverseosmosis membrane units 370 are BW30-4040 reverse osmosis elements fromFilmtec, 7200 Ohms Lane, Minneapolis, Minn. The preferred Teflon tubing184 has a 0.25 inch O.D. and is number AT250-030 from Fluoroware, Inc.,102 Jonathan Boulevard North, Chaska, Minn. The preferred lasers are No.LM-2U manufactured by Applied Laser Systems. The carbon block filter 178may be a model CBC-BBS filter from Ametek, Plymouth Products Division,502 ; Indiana Avenue, Sheboygan, Wis. The pump 118 is preferable a onehorsepower pump. The bladder tank 158 is preferably a 3-gallon bladdertank.

The preferred embodiment of the present invention has many advantages.It is a completely self contained system. There is no remote equipment,controls or storage vessels present that may be adjusted inadvertentlyor become contaminated. The apparatus has an automatic shut-off foreither low inlet pressure or high conductivity in the purified water.Also, "Out of Service" lights come on if an automatic shut-off conditionoccurs. The counter 62 is preferably equipped with auxiliary batterypower backup. The microprocessor preferably includes a memory protectedagainst power failure. The 30 second timer on the dispensing door allowscomplete operation of all dispensing controls. After 30 seconds,however, the door must be opened and closed again to reset the 30 secondcontrol timer (See Line 26 of FIG. 3c). The 30 second timer on thewash/rinse door allows complete operation of wash/rinse control. After30 seconds, the door must be opened and closed again to reset 30 secondcontrol timer (See Line 17 of FIG. 3b).

The use of a fast-fill valve 186 and a slow fill valve 188 allows fastfilling of container 18 until near the point at which the container 18is full. The slow rate of filling at the end prevents splashing and,more importantly, slows down the flow of water through fill-tube 36 sothat when slow fill valve 188 closes, the water does not all run out offill tube 36. The water remaining in fill-tube 36 prevents air andairborne contaminants from traveling up tube 192 and contaminatingvalves 186 and 188.

The invention is designed for use at retail outlets where customers filltheir containers and pay for the purified water as they go through acheck-out line. Other places where the invention may be used includeconvenience stores, office complexes, multi-family dwellings, industrialplants, day care programs and educational facilities.

It should be appreciated that the apparatus and methods of the presentinvention are capable of being incorporated in the form of a variety ofembodiments, only a few of which have been illustrated and describedabove. The invention may be embodied in other forms without departingfrom its spirit or essential characteristics. The described embodimentsare to be considered in all respects only as illustrative and notrestrictive, and the scope of the invention is, therefore, indicated bythe appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

We claim:
 1. A water purification and dispensing apparatus for filling a container, comprising:a water inlet for obtaining unpurified water from a supply source; a water purification system including means for filtering the unpurified water to obtain purified water; a water outlet which directs the purified water to the container; means for controlling said water purification system including means for selectively providing a demand condition for the purified water, said system including means for directing the purified water to said water outlet after said providing means provides said demand condition; and means for recycling purified water in said water purification system, said recycling means including means for bypassing said water outlet, said bypassing means having first means for flushing said filtering means with the purified water, said recycling means being responsive to said providing means after said providing means provides said demand condition and before said directing means directs the purified water to said water outlet.
 2. The apparatus in accordance with claim 1 wherein said bypassing means further has second means for flushing said filtering means with the purified water after said providing means ends said demand condition.
 3. The apparatus in accordance with claim 1 wherein said filtering means includes a reverse osmosis element which outputs a purified water stream and a concentrate stream and wherein said system further includes means for dividing said concentrate stream into a waste stream and a recirculation stream, the recirculation stream being directed by said system through said reverse osmosis element again.
 4. The apparatus in accordance with claim 1 wherein said system includes means for regulating pressure of the unpurified water to a first predetermined value and means for increasing the pressure to a second predetermined value before the unpurified water passes through said filtering means.
 5. The apparatus in accordance with claim 1 wherein said water outlet includes a downwardly-directed fill tube, said controlling means including means for fast filling said container and means for slow filling said container, said fill tube having an internal diameter such that said fill tube retains purified water therein when said slow filling means is turned off.
 6. The apparatus in accordance with claim 5 including a compartment for receiving the container, said compartment having a top with first, second, and third openings, said fill tube ending above said second opening so that said fill tube is protected by said top from users touching said fill tube, said apparatus further including a pair of light sources, said light sources directing light through said first and third openings, said first and third openings being equally spaced on opposite sides of said second opening so that an upper opening in said container can be centered between said first and third light sources in order to receive purified water flowing through said second opening.
 7. The apparatus in accordance with claim 1 wherein said water purification system includes a mineral addition system for adding minerals to the purified water and means for restricting flow to a predetermined rate so that a known flow rate of purified water is received by said mineral addition system.
 8. The apparatus in accordance with claim 7 wherein said mineral addition system adds calcium chloride, potassium chloride and magnesium chloride to the purified water at an approximate weight ration of 60:20:20 up to a total dissolved solids level of approximately 100 ppm.
 9. The apparatus in accordance with claim 8 wherein said water purification system includes downstream from said mineral addition system means for mixing said mineralized, purified water.
 10. The apparatus in accordance with claim 1 wherein water purification system includes a tubular helix upstream from said water outlet and an ultraviolet light source located to direct ultraviolet light through the purified water in said helix before the purified water flows through said water outlet, said helix providing a relatively long residence time for the purified water to be exposed to the ultraviolet light, the ultraviolet light functioning to destroy bacteria.
 11. A process for purifying and dispensing water comprising the steps of:obtaining unpurified water from a supply source; providing a demand condition for purified water; filtering the unpurified water through filtering means to obtain purified water, said filtering means including a reverse osmosis element which creates the purified water and a concentrate; on receiving the demand condition, recycling purified water from the filtering means by recirculating the purified water from the filtering means back through the filtering means to flush said filtering means; following said recycling step, directing the purified water to a water dispensing arrangement; and subsequent to demand no longer being present, stopping water flow.
 12. The process of claim 11 wherein the water flow stopping step subsequent to demand no longer being present and prior to actually stopping water flow, includes the step of recirculating purified water from the filtering means back through the filtering means to flush the filtering means. 